Written by Adam Tamburin, The Tennessean and Amanda Haggard, Gannett Tennessee

Investigators familiar with the three water-related deaths that cast a pall over Middle Tennessee's Labor Day weekend said it does not appear that alcohol played any role in the tragedies.

Two men drowned Monday afternoon and a third man died in a boating accident Sunday.

Matthew Grissom drowned while swimming at Walter Hill Dam in Rutherford County. Abdala Amsabil died while swimming at Burgess Falls State Park near Cookeville. And Harvie C. Butler died while boating on J. Percy Priest Lake.

"For me, it feels like I've lost a child and a friend and a brother all at the same time," Terry Tatum said of Butler. The two men worked together at Keller Williams Realty in Murfreesboro.

Butler, a 39-year-old La Vergne man, was thrown overboard when two boats collided near the Four Corners Marina in Antioch. Officials found his body in the lake Monday morning.

Butler was with a group of friends celebrating an annual "guys weekend" on the lake, said Tatum, who was not on the boat. They were headed back home before the fatal collision.

"He was with people that he cared about and who cared about him," Tatum said.

It remains unclear what caused the boat crash that killed Butler and wounded four others. Investigators are looking into the possibility that rainy weather was a factor, according to TWRA spokesman Doug Markham.

The investigation will continue through the week, as officials with the Tennessee Wildlife Resources Agency gather evidence from the mangled boats and conduct more witness interviews.

"Once we have those two things together we can make a better determination as to how the boats collided," said TWRA boating accident investigator Matt Majors.

Butler's death marks the state's 18th fatality in a boating accident this year, according to the TWRA. In 2012, boating accidents claimed 18 people in Tennessee through the calendar year.

Two people died in Tennessee boat crashes during Labor Day weekend last year, according to the TWRA.

Uncle: A leg cramp

Divers found Grissom's body hours after he disappeared beneath the surface at Walter Hill Dam in northern Rutherford County.

Grissom, an 18-year-old Smyrna High School senior, was swimming with friends when he got a leg cramp and slipped underwater, according to his uncle CJ Jatala.

"The cramp is what caused him to get pulled under," Jatala said. "People tried to save him, but he was fighting it so bad and panicking so hard that he just went down," Jatala said.

Now Grissom's family is struggling to pay for the funeral, which is scheduled for Saturday in Smyrna.

"His mother has literally no money," Jatala said. "She had life insurance until she lost her job, but now she has no idea how she'll pay for all of it."

An account for donations has been set up at First Southern National Bank branches. Donations will be accepted under the account name Thomas Coates-Jatala 94.

Counselors were on hand at Smyrna High on Tuesday, and the school plans to offer assistance throughout the week.

"He was a good student," Jatala said of Matthew. "He was just getting ready to go into the military, but he wanted to be a minister and to help others in any way he could."

Sgt. Kyle Evans with the Murfreesboro police department called the investigation "standard as no foul play is suspected at this point."

No foul play

Officials found Amsabil, 22, Monday afternoon in 11 feet of water at Burgess Falls State Park, eight miles south of Cooke­ville. Although it is unclear what caused the Nashville man, who was not wearing a life jacket, to go underwater, further investigation is not likely.

"Since there was no foul play, there will be no formal investigation," said Kelly Brockman, spokeswoman for the Tennessee Department of Energy and Conservation.

"Our hearts go out to the families of those that lost their lives over the weekend due to water-related accidents," said Beth Toll, spokeswoman for Nashville's Red Cross chapter. "The Red Cross strongly encourages families to make water safety a priority and to know how to respond in a water emergency."